The present invention relates to an automatic running work vehicle, and more particularly to a work vehicle adapted to automatically run on a work site of specified range in accordance with a running sequence for the vehicle to run a plurality of predetermined running courses based on the result obtained by detecting the boundary between a worked area and an unworked area with follower sensors during running and in accordance with a direction change sequence for the vehicle to move from one completed running course to the next running course.
Conventionally, when an automatic running work vehicle of this type, such as a mowing vehicle or like ground working vehicle, is to work automatically the ground at a work site of specified range the surroundings of which have been worked on in advance, the work area is divided into a plurality of running courses each corresponding to the working width, and the vehicle is controlled to automatically run the courses one after another.
The vehicle runs the courses according to a reciprocating running sequence in which case the running courses are set in parallel such that the vehicle changes its orientation through 180 degrees when moving from course to course, or according to a sequence in which case the courses extend along the outer periphery of the work area are arranged successively inward of the area for the vehicle to move from course to course by changing its orientation through 90 degrees. In either mode, the vehicle runs each course while being subjected to follower steering control based on the result obtained by detecting the boundary of the course with follower sensors, so that the vehicle runs with relatively small amounts of deviation from the desired direction. However, when changing the direction at the end of each course, the vehicle body, which is generally subjected to a definite pattern control according to a preset sequence, is likely to zigzag excessively before moving along the boundary of the next cource owing to deviation, thereby leaving irregular work traces in the vicinity of the ends of the courses.